Crystal structure of [3,10-bis(4-fluorophenethyl)-1,3,5,8,10,12-hexaazacyclotetradecane]nickel(II) diperchlorate

The square-planar nickel(II) title complex, [Ni(C24H36F2N6)](ClO4)2 or [NiL](ClO4)2 (L = 3,10-bis(4-fluorophenethyl)-1,3,5,8,10,12-hexaazacyclotetradecane) was synthesized by a one-pot reaction of template condensation and its X-ray crystal structure was determined. The nickel(II) ion lies close by a twofold axis and the complex displays whole-molecule disorder. Ligand L, a hexaazacyclotetradecane ring having 4-fluorophenethyl side chains attached to uncoordinated nitrogen atoms, adopts a trans III (R,R,S,S) configuration. The average Ni—N bond distance is 1.934 (9) Å, which is quite similar to those of other nickel(II) complexes with similar ligands. The nickel(II) ion is located 0.051 (7) Å above the least-squares plane through the four coordinated N atoms. The average C—N bond distance and C—N—C angle involving uncoordinated nitrogen atoms are 1.425 (12) Å and 118.0 (9)°, respectively, indicating a significant contribution of sp 2 hybridization for these N atoms. The intermolecular N—H...O, C—H...O/F hydrogen bonds of the complex form a network structure, which looks like a seamless floral lace pattern.

2H-[1,3]Thiazolo[5,4,3-ij]quinolin-3-ium chloride monohydrate

The structure of the title hydrated molecular salt, C10H8NS+·Cl−·H2O, obtained by the reaction of sodium quinoline-8-thiolate Na(Quin-8-S) with CH2Cl2 and an aqueous solution of [Bu4N]Cl, contains π-stacked cations [plane-to-plane separation = 3.338 (4)–3.356 (4) Å] and features chains built by alternating Cl− anions and H2O molecules connected by O—H...O hydrogen bonds. The cation shows whole-molecule disorder over two flipped orientations in a 0.853 (3):0.147 (3) ratio.

Crystal structures of two heterotrimetallic dysprosium–manganese–sodium 12-metallacrown-4 complexes with the bridging ligands 3-hydroxybenzoate and 4-hydroxybenzoate

The syntheses and crystal structures for the compounds tetra-μ-aqua-tetrakis{2-[azanidylene(oxido)methyl]phenolato}tetrakis(μ2-3-hydroxybenzoato)dysprosium(III)tetramanganese(III)sodium(I) N,N-dimethylacetamide decasolvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·10C4H9NO or [DyIIINa(4-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·10DMA, 1, and tetra-μ-aqua-tetrakis{2-[azanidylene(oxido)methyl]phenolato}tetrakis(μ2-3-hydroxybenzoato)dysprosium(III)tetramanganese(III)sodium(I) N,N-dimethylformamide tetrasolvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·4C3H7NO or [DyIIINa(3-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·4DMF, 2, and where MC is metallacrown, shi3− is salicylhydroximate, 3-OHben is 3-hydroxybenzoate, DMA is N,N-dimethylacetamide, 4-OHben is 4-hydroxybenzoate, and DMF is N,N-dimethylformamide, are reported. For both 1 and 2, the macrocyclic metallacrown consists of an [MnIII—N—O] ring repeat unit, and the domed metallacrown captures two ions in the central cavity: a DyIII ion on the convex side of the metallacrown and an Na+ ion the concave side. The MnIII ions are six-coordinate with an elongated tetragonally distorted octahedral geometry. Both the DyIII and Na+ ions are eight-coordinate. The DyIII ions possess a square-antiprismatic geometry, while the Na+ ions have a distorted biaugmented trigonal–prismatic geometry. Four 3-hydroxybenzoate or 4-hydroxybenzoate ligands bridge each MnIII ion to the central DyIII ion. For 1, whole-molecule disorder is observed for the main molecule, excluding only the DyIII and Na+ ions, and the occupancy ratio refined to 0.8018 (14):0.1982 (14). Three DMA molecules were refined as disordered with two in general positions by an approximate 180° rotation and the third disordered twice by general disorder as well as by an exact 180° rotation about a twofold axis that bisects it. The occupancy ratios refined to 0.496 (8):0.504 (8), 0.608 (9):0.392 (9), and 2×0.275 (7):2×0.225 (7), respectively. For 2, segments of the metallacrown are disordered including the DyIII ion, one of the Mn ions, two of the Mn-bound 4-hydroxybenzoate ligands, the Mn-bridging salicylhydroximate ligand, and portions of the remaining three shi3− ligands. The occupancy ratio for the metallacrown disorder refined to 0.849 (9):0.151 (9). Two DMF solvent molecules are also disordered, each over two orientations. The disorder ratios refined to 0.64 (3):0.36 (3) and to 0.51 (2):0.49 (2), respectively. For 2, the crystal under investigation was refined as a non-merohedric twin by a 90° rotation around the real a axis [twin ratio 0.9182 (8):0.0818 (8)].

Synthesis and crystal structure of two manganese-based 12-metallacrown-4 complexes: Na2(3-chlorobenzoate)2[12-MCMn(III)N(shi)-4](DMF)6 and MnNa(3-chlorobenzoate)3[12-MCMn(III)N(shi)-4](DMF)(H2O)4·4DMF·0.72H2O

Similar synthetic schemes yield two different metallacrown (MC) complexes: bis(μ-3-chlorobenzoato)hexakis(dimethylformamide)tetrakis(μ4-N,2-dioxidobenzene-1-carboximidato)tetramanganese(III)disodium(I), [Mn4Na2(C7H4ClO2)2(C7H4NO3)4(C3H7NO)6] or Na2(3-chlorobenzoate)2[12-MCMn(III)N(shi)-4](DMF)6, 1, and tetra-μ-aqua-tris(μ-3-chlorobenzoato)(dimethylformamide)tetrakis(μ4-N,2-dioxidobenzene-1-carboximidato)pentamanganese(III)sodium(I) dimethylformamide tetrasolvate 0.72-hydrate, [Mn5Na(C7H4ClO2)3(C7H4NO3)4(C3H7NO)(H2O)4]·4C3H7NO·0.718H2O or MnNa(3-chlorobenzoate)3[12-MCMn(III)N(shi)-4](DMF)(H2O)4·4DMF·0.72H2O, 2, where shi3− is salicylhydroximate and DMF is N,N-dimethylformamide. Both complexes have the same framework consisting of four MnIII ions in the MC ring and four shi3− ligands, resulting in an overall square-shaped molecule. The MnIII ions are either five- or six-coordinate with elongated bond lengths in the apical or axial direction, respectively. The structure of 1 is nearly planar, and the MC binds two Na+ ions on opposite faces of the MC central cavity. The 3-chlorobenzoate anions also bind on opposite faces of the MC and form bridges between the central Na+ ions and the ring MnIII ions. For 1 the metallacrown molecule, except for the central Na+ ion, exhibits whole molecule disorder over two sets of sites. Both moieties are centrosymmetric and are related to each other by a pseudo-mirror operation with opposite sense of rotation around the Na...Na axis. The occupancy ratio of the main disorder of the metallacrown molecules and 3-chlorobenzoate anions refined to 0.9276 (9):0.0724 (9). The structure of 2 is slightly domed, and the MC binds both an MnII ion and an Na+ ion in the MC central cavity. The MnII ion is located on the convex side of the MC, while the Na+ ion binds to the concave side. Complex 2 represents the first instance of a [12-MCMn(III)N(shi)-4] molecule binding both 3d transition metal and alkali metal ions in the central cavity. In addition, three 3-chlorobenzoate anions bind on the convex side of the MC and connect the MnII ion to three of the ring MnIII ions.

Whole-molecule disorder of the Schiff base compound 4-chloro-N-(4-nitrobenzylidene)aniline: crystal structure and Hirshfeld surface analysis

In the crystal of the title Schiff base compound, C13H9ClN2O2, [CNBA; systematic name: (E)-N-(4-chlorophenyl)-1-(4-nitrophenyl)methanimine], the CNBA molecule shows whole-molecule disorder (occupancy ratio 0.65:0.35), with the disorder components related by a twofold rotation about the shorter axis of the molecule. The aromatic rings are inclined to each other by 39.3 (5)° in the major component and by 35.7 (9)° in the minor component. In the crystal, C—H...O hydrogen bonds predominate in linking the major components, while weak C—H...Cl interactions predominate in linking the minor components. The result is the formation of corrugated layers lying parallel to the ac plane. The crystal packing was analysed using Hirshfeld surface analysis and compared with related structures.

Hypervalent organoselenium compounds stabilized by intramolecular coordination: synthesis and crystal structures

Two novel hypervalent selenium(IV) compounds stabilized by intramolecular interactions, namely 6-phenyl-6,7-dihydro-5H-2,3-dioxa-2aλ4-selenacyclopenta[hi]indene, C14H12O2Se, 14, and 5-phenyl-5,6-dihydro-4H-benzo[c][1,2]oxaselenole-7-carbaldehyde, C14H12OSe2, 15, have been synthesized by the reaction of 2-chloro-1-formyl-3-(hydroxymethylene)cyclohexene with in-situ-generated disodium diselenide (Na2Se2). The title compounds were characterized by FT–IR spectroscopy, ESI–MS, and single-crystal X-ray diffraction studies. For 14, there is whole-molecule disorder, with occupancies of 0.605 (10) and 0.395 (10), a double bond between C and Se, and the five-membered selenopentalene rings are coplanar. The packing is stabilized by π–π stacking interactions involving one of the five-membered Se/C/C/C/O rings [centroid–centroid (Cg...Cg) distance = 3.6472 (18) Å and slippage = 1.361 Å], as well as C—H...π interactions involving a C—H group and the phenyl ring. In addition, there are bifurcated C—H...Se,O interactions which link the molecules into ribbons in the c direction. For 15, the C—Se bond lengths are longer than those of 14. The two five-membered rings are coplanar. There are no π–π or C—H...π interactions; however, molecules are linked by C—H...O interactions into centrosymmetric dimers, with graph-set notation R 2 2(16).

Green synthesis and crystal structure of 3-(benzothiazol-2-yl)thiophene

The title compound, C11H7NS2, was prepared in high yield (87%) using a solvent-free microwave-assisted synthesis. The structure shows whole-molecule disorder with occupancies for two orientations (A and B) of 0.4884 (10) and 0.5116 (10), respectively. The thiophene and benzothiazole rings are almost planar and make dihedral angles of 10.02 (18) and 12.54 (19)° for orientations A and B, respectively. Slipped π–π stacking between the aromatic rings, together with C—H...π, C—H...S and C—H...N interactions, result in a herringbone motif in the crystal packing.

Crystal structures of three sterically congested disilanes

In the three sterically congested silanes, C24H38Si2(1) (1,1,2,2-tetraisopropyl-1,2-diphenyldisilane), C24H34Br4Si2(2) [1,1,2,2-tetrakis(2-bromopropan-2-yl)-1,2-diphenyldisilane] and C32H38Si2(3) (1,2-di-tert-butyl-1,1,2,2-tetraphenyldisilane), the Si—Si bond length is shortest in (1) and longest in (2), with (3) having an intermediate value, which parallels the increasing steric congestion. A comparison of the two isopropyl derivatives, (1and2), shows a significant increase in the Si—C(ipso) distance with the introduction of bromine. Also, in the brominated compound2, attractive intermolecular Br...Br interactions exist with Br...Br separationsca0.52 Å shorter than the sum of the van der Waals radii. In compound2, one of the bromoisopropyl groups is rotationally disordered in an 0.8812 (9):0.1188 (9) ratio. Compound3exhibits `whole molecule' disorder in a 0.9645 (7):0.0355 (7) ratio with the Si—Si bonds in the two components making an angle ofca66°.

7-Bromo-2,3-bis[(prop-2-yn-1-yl)sulfanyl]pyrido[2,3-b]pyrazine

In the title compound, C13H8BrN3S2, one propynyl substituent lies approximately in the plane of the pyridopyrazine ring system, while the other is twisted away from this plane. In the crystal, offset π–π stacking interactions between the pyridine and pyrazine rings with a centroid–centroid distance of 3.740 (1) Å stack the molecules along thea-axis direction. At the conclusion of the initial refinement, a significant residual peak remained in the difference map. This suggested an alternate location for the Br atom but at a very low occupancy. Further refinement with Br disordered over two sites yielded a population ratio for the two Br sites of 97:3. As the refined location of the minor Br site leads to unequal C—C—Br angles, we feel that the results indicate a `whole molecule' disorder rather than the presence of a minor amount of an isomer. Unfortunately, the very low amount of the second component of the disorder prevented the location of any of its other atoms.